While you wear this pendant, you stabilize whenever you are dying at the start of your turn. In addition, whenever you roll a Hit Die to regain hit points, double the number of hit points it restores.
Notes: Healing, Warding, Jewelry
i dont think so. you can still be killed by enough damage to take you to negativeyour max health, by things attacking after you've fallen but before you've stabilized, disintegrate, etc. not to mention that it requires attunement and does nothing for u when u dont need to be stabilized or if ur not healing from hit dice. not saying those aren't extremely useful, but many people would probably replace this item with something that aides their abilities at some if given the choice.
Personally, I find that imposing a point of Exhaustion each time this stabilization occurs helps balance this item. If they go down and up 6 times they die anyway... Food for thought. This item is incredibly useful for parties from Levels 1-7, afterwards it has diminishing returns.